[geeks] FeeCee Power Supply Design

[Chad McAuley]

On 9/18/07, Sridhar Ayengar <ploopster at gmail.com> wrote:
> I'm in the market for a beefier power supply for my multimedia box,
> since it's already having stability issues with the load it's currently
> supporting, and I'm about to add four hard drives to the mix.
>
> I saw this supply:
> http://www.antec.com/us/productDetails.php?ProdID=23650#
>
> Its specs list that it has three +12V rails at 19A each.  My video card
> requires 26A all by itself.  How will the supply be set up usually?  I
> hope they don't just partition it by putting some of the power
> connectors on each supply rail.  That would make this 650W supply too
> weak to power my video card.
>
> Any ideas?
>
> Peace...  Sridhar


I'm not sure how Antec does it, but iIRC the most common design is to
just have multiple "virtual" 12V rails.  PSUs designed this way only
have one 12V source (i.e., only one transformer that steps down the
voltage) that is then split into X circuits that each have current
limiters on them, with each circuit powering different connectors.
I'm not seeing it on their website, but several reviews I found of
that unit mention a bit on the specs sticker saying that the maximum,
combined current for 12V1, 12V2, and 12V3 is 52A, which makes me think
this is a virtual rail design.